An operation device including a touch panel or an operation panel having operation buttons is generally provided at a printer, a scanner, a telephone, a facsimile machine, etc. This operation device is desirably arranged on an upper surface of the printer in view of operability of the touch panel or the operation button or a size of the printer.
The operation panel may be operated from the upper side of the device and also operated from the front side of the device. Therefore, when the operation panel faces above, operability from the front side of the device becomes worse. Similarly, when the operation panel faces the front surface side of the device, operability from the upper surface side of the device becomes worse. Therefore, there has been proposed an operation device in which an operation panel is disposed a device body capable of falling and rising with respect to the device body, and a posture of the operation panel can be changed to direct the operation panel in any direction of the upper surface side of the device or the front surface side of the device. Such an operation device includes a mechanism capable of holding the operation panel in any posture, the so-called tilt mechanism.
JP-A-10-63192 describes an angle holding mechanism in a tilt mechanism for holding a display unit at a desired inclination angle. This angle holding mechanism holds the display unit at the desired inclination angle by locking of a rack to a stopper. Also, when a release button of a release portion is pressed and operated, the locking of the rack to the stopper is released, and the display unit can be rotated.
JP-A-11-354941 describes a hinge mechanism in the portable electronic device, in which a mechanism holds a portable electronic device at any angle so as not to move in a direction of closing the portable electronic device by engagement between a ratchet and a latching potion. When the portable electronic device is moved to 90°, the latching portion deviates from a locus of the ratchet and the portable electronic device can be moved in the closed direction.